1) Behringer ADA8000
I've tested with a loopback of a mono wav-file. The original in 44,1khz/16bit, recoring in 44,1khz/24bit.
I've done 40 passes of each.
The original is normalized to rms-value , and each take is then adjusted to same value (0,1ms window. This gives peaks within 0,8db). Setup is within +-1,5db for in/out.
The playlist is wav 44,1khz/16bit with peaks around -2dbfs.
Edit: I've just discovered Soundcload streams in 128kbps. That's just lame for this kind of listening. Will provide some better listening.